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C. E. PETERSON. TRACKING CONTROL MECHANISM FOR PIANO PLAYERS.

APPLICATION FILED JAN. 2Z|1918.

Patented June 24, 1919.

EIIDDOODUD Tnl/Pn or 12. f.

258 &

UNITED STATES PATENT OFFICE.

CLAUS E. PETERSON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO IVERSON PIANO PLAYER COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

TRACKING-CONTROL MECHANISM FOR PIANO-PLAYERS.

Application filed January 22, 1918.

To all whom it may concern:

Be it known that I, CLAUS E. PETERSON, a citizen of the United States, residing at \Vorcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Tracking-Control Mechanism for Piano- Players, of which the following is a specification accompanied by drawings forming a part of the same.

The present invention relates to automatic piano players, and has particular reference to the mechanism employed therein for maintaining a correct tracking relation between the traveling note sheet and the apertured tracker bar.

Prior devices of this class have been characterized by a profusion of complicated and delicate pneumatically operated parts, including in most cases a plurality of motor bellows or operating pneumatics and a plurality of valves associated with each, the latter for the purpose of communicating a deflection of the note sheet to said motor bellows, whereby to produce therein an impulse adapted to return the sheet to its normalposition. The objection to such prior devices, 1n addltion to their-extreme complication, is found in the length of time required to actually correct a deflection of the sheet, due to the interposition of so many instrumentalities, all pneumatically operated, between the place where the aberration or deflection occurs and the force which is ultimately applied to correct the same.

The present invention aims to overcome these vital ObJGCtlOIlS to previous devices of this class, by eliminating wholly the use of valves and actuating pneumatics or motor bellows in this connection, thereby simplifying and reducing the cost of the mechanism and at the same time making its operation instantly and positively responsive to the deflection of the sheet. The invention is fully set forth, hereinafter, reference being had to the accompanying drawings, in Which Figure 1 is a front View of a tracking control mechanism embodying my invention, certain parts being shown in section. to (118 Specification of Letters Patent.

Patented June 24, 1919.

Serial No. 213,158.

close more clearly the operation of the mechamsm.

Fig. 2 is a detached view in front elevation of a diaphragm box shown in section in Fig. 1.

Fig. 3 is a cross section of said box, the section being at right angles to the section of Fig. 1.

Fig. at is a detached view showing the rear side of one end of the tracker bar.

Fig. 5 is a vertical sectional view through the tracker bar, in the plane of the broken line 55, Fig. I.

Like reference characters refer to like parts in the different figures.

As shown in Fig. 1, an ordinary framework 1 provides for the support of the usual delivering music spool 2 and receiving music spool 3. During the operation of playing a selection from the perforated music sheet 4, the latter is drawn across the face of a perforated tracker bar 5 by power applied to the receiving music spool 3 in the usual and well known manner. The delivering music spool 2 on which the sheet 4: is carried in a roll is removable from the machine in the usual manner, and when placed in the machine said spool 2 is free to move endwise in either direction within certain limits, its movement toward the left serving to compress a spiral spring 6 and its movement toward the right being against the tension of a blade spring 7. The blade spring 7 is supported on a fixed. framework, with its free end bearing against an arm 8 which in turn bears against a shaft 9, the latter having clutching spurs 10 for the spool 2 when the latter is inserted in place, in the usual man ner. In inserting said delivering spool 2 in the machine, the left hand spindle 11 is pushed to the left against the force of spring 6 by pressing the end of the spool against said spindle. This enables the right hand end of the spool 2 to be engaged by the clutching spurs 10 of shaft 9 without shifting said shaft 9. The arm 8 above referred to, is fixed to a rod 12, the latter adapted to slide longitudinally in the framework 1, and having at its other end a projection 13 which engages a groove 14 in a collar or sleeve 15, the latter being loose on spindle 11. Ad acent the sleeve/15 is a fixed collar 16 on spindle 11, and in the movement of said, spindle to permit the insertion of spool 2, as above described, the sleeve 15 remains stationary, only the collar 16 moving to the left. Then the spool is ina place, the return of spindle 11 to the position shown in Fig. 1,'br1ngs the fixed collar 16 up against the loose sleeve 15.

In this way provision is made for the insertion of the spool 2 without disturbing the connection between the spindles 9 and 11, said connection being embodied in the rod 12. When the spool 2 is in place, the tension of spring 7 is substantially equal to the tension of spring 6, so that in the playing of the instrument the delivering spool 2 is held balanced between the two springs 6 and 7.

Upon the rear side of the tracker bar 5 are provided two bent levers 17, 17, each being pivoted at 18 to the tracker bar, as shown in Fig. 4. One arm of the bent lever 17 extends upwardly to the top of the tracker bar, and is there bent forwardly at right angles, terminating in a cap or valve 19, having preferably a pad of leather or felt 20 on its under side. Each cap or valve 19' thus formed coiiperates with the upper end of a vent hole 21 formed in the tracker bar and communicating with a pipe 22, and in the normal position of each lever 17 the vent hole 21 associated therewith is securely closed by the pad 20. The other arm of each. bent lever 17 is provided with a projecting prong 23 which extends forward of the tracker bar a short distance beyond the plane of the perforated music sheet 4. The distance between the prongs 23, when the valves are in closed position, is just equal to the width of the perforated sheet 4, each valve being held closed by the blade spring 24, Fig. 4. The right hand pipe 22 leads to a chamber 25 formed on the under side of a diaphragm box 26, and the left hand pipe 22 leads to a similar chamber 25 which is wholly independent of the first chamber 25. The two chambers 25, 25 are separated from the interior of the box 26 by means of a pair of diaphragms 27 and 27, respectively, the latter carrying rods 28, 28, which project slidably through suitable bearings in the top of box 26, and terminate in slotted knobs 29, 29. The three arm lever 80 pivoted at 31 above the box 26, has a vertically disposed arm 32 which engages the groove 14 of sleeve 15, as shown in Fig. 1. The two lateral arms of lever 30 are'embraced loosely by the slots of the knobs 29 and 29, on each side of the pivotal center of said lever.

The interior of box 26 communicates through a pipe 33 with the usual exhausting or vacuum devices of the instrument, not.

shown, whereby a constant tension is maintained within the box. Provision is made for substantially equalizing the normal pressures on opposite sides of the diaphragms 27 and 27 by bleed apertures 34, one of which is shown in Fig. 3, adapted to communicate through pipes 35 with the chambers 25 and 25. In the normal and correct tracking relation of music sheet 4 the parts remain in the positions illustrated in Fig. 1, both diaphragms being depressed due to the weight of the parts carried thereby. So long as the sheet 4 moves in its normal path between the prongs 23, 23, the pneumatically operated parts of the mechanism remain in this illus' trated position. If the music sheet for any reason begins to track unevenly, so as to be deflected toward the left, Fig. 1, the left hand valve 19 is immediately lifted by the rocking of its lever 17, caused by the pressure of the left hand edge of the music sheet against prong 23. This results in a rush of air into the associated vent hole 21 and pipe 22 which lifts the diaphragm 27 and rocks the three arm lever 30 in a clockwise direction. It will be understood that the bleed 34 retards the building up of any pressure within the box 26 during this movement of the diaphragm, although allowing the admitted air to be gradually drawn 0]? by the exhausting devices after the deflection of the sheet has been corrected.

This clockwise movement of the lever 30 is communicated to the loose sleeve 15 and by it through the rod 12 to the arm 8, which is carried to the right, Fig. 1, so as to unbalance the spring pressure acting on spool 2, thereby allowing spring 6 to exert its pressure and to move the spool 2 and spindles 9 and 11 to the right. Such right hand movement immediately rest-ores the normal tracking relation of the sheet, whereupon the parts return automatically to the positions illustrated in Fig. 1. Similarly, if the sheet 4 undergoes a deflection to the right, Fig. 1, the inrush of air through the right hand valve 19, vent hole 21 and pipe 22, causes an elevation of diaphragm 27, which moves the lever 3.0 in a counter-clockwise direction. This movement, by the engagement of sleeve 15 with stationary collar 16, draws the spin dle 11 to the left, compressing the spring 6, and allowing the spring 7 to move the spool 2 to the left, thereby correcting the tracking relation of sheet 4. The return of the sheet to correct tracking relation effects the return of all the parts to the positions shown in Fig.

1, as above described.

rect any aberration in the movement of sheet 4 over tracker bar 5.

I claim,

1. Tracking control' mechanism for piano players and the like, comprising a pair of flexible diaphragms operable by a variation of air pressure on opposite sides thereof,

means for actuating one of said diaphr'agms by the lateral deviation of the note sheet 1n one direction, means for actuating the other tracker bar, one of said parts being longitudinally movable, normally balanced springs applied to the ends of said longitudinally movable part and acting in op osition to each other, a pair of flexible (iiaphra'gms each maintained in inoperative position during the normal tracking movement of the note sheet, means for actuating one of said diaphragms by the deviation of the note sheet in one direction, means for actuating the other of said diaphragms by the deviation of the note sheet in the opposite direction, and means operatively connected directly with said diaphragms for relieving the pressure of one of said springs against said longitudinally movable part to permit the other of saidsprings to restore the note sheet to its normal tracking relation to the tracker bar.

3. In a mechanism of the class described, a delivery spool, a receiving spool and a tracker bar, one of said parts being longitudinally movable, normally balanced springs acting in opposite directions against said longitudinally movable part, a pair of flexible diaphragms each maintained in an inoperative position during the normal movement of the note sheet over the tracker bar, means for actuating one of said diaphragms by the lateral deviation of the note sheet in one direction, means for actuating the other diaphragm by the lateral deviation of the note sheet in the opposite direction, a three armed lever pivotally supported above said diaphragms, means operatively connecting said lever with said diaphragms to rock said lever as one or the other of said diaphragms is actuated, and means operatively connected With said pivoted lever for destroying the balance of said oppositely acting springs.

4. In a mechanism of the class described, a receiving spool, delivery spool and a tracker bar, one of said parts being longitudinally movable, normally balanced springs acting in opposite directions against said longitudinally movable part, two pairs of chambers, a flexible diaphragm dividing the chambers of each pair, means for varying the air pressure upon one side of each of said diaphragms controlled by the lateral deviation of a note sheet as it moves over the tracker bar, means for relieving the pressure of one of said normally balanced springs as one of said diaphragms is actuated, and means for relieving the pressure of the other of said normally balanced springs as the other of said diaphragms is actuated.

5. In a mechanism of the class described, a delivery spool for a note sheet capable of endwise movement, a tracker bar, a rotatable receiving spool for drawing the note sheet over the tracker bar, a pair of rotatable spindles supporting said delivery spool, a pair of normally balanced springs acting in opposite directions against said spindles, means for relieving the pressure of one of said springs controlled by the lateral deviation of the note sheet in one direction, and means for relieving the pressure of the other of said springs controlled by the lateral deviation of the note sheet in the opposite direction.

6. In a mechanism of the class described, a delivery spool, a tracker bar, a rotating receiving spool for drawing a note sheet over the tracker bar, a box inclosing an exhaust chamber, a pair of chambers below said exhaust chamber, flexible diaphragms separating said chambers from said exhaust chamber, rods. supported on said diaphragms, a rocking three armed lever having two of its arms pivoted to said rods and having its third arm operatively connected With mechanism for controlling the movement of a note sheet over the tracker bar.

7. In a mechanism of the class described, a delivery spool, a receiving spool and a tracker bar, one of said parts being longitudinally movable, normally balanced springs acting in opposite directions against said movable part, a pair of diaphragms maintained in an inoperative position during the normal tracking movement of a note sheet, means for actuating one of said diaphragms by the lateral deviation of the note sheet in one direction, means for actuating the other of said diaphragms by the lateral deviation of the note sheet in the opposite direction, means operatively connected with one of said diaphragms for correcting the deviation of the note sheet in one direction, and means operatively connected with the other of said diaphragms for correcting the deviation of the note sheet in the opposite direction.

8. In a mechanism of the class described, a delivery spool, a receiving spool and a tracker bar, one of said parts being longitudinally adjustable, a pair of normally balsure of the other of said springs controlled by the lateral deviation of the note sheet in the opposite direction. CLAUS E. PETERSON. Witnesses:

PENELOPE OOMBERBAOH, GEOA H. KENN DY, Jr.

anced springs presslng in opposite directions against said longitudinally movable part, a mechanism for relieving the pres sure of one of said springs controlled by the lateral deviation of the note sheet in ene direction, and means for relieving the wee {we cents each, by addressing the Commissioner ofratents,

Copies of this patent may be obtained for t I Waghington, I). 0,? 

